Download Test on chapter (1)

Test on Chapter (1)
First question:
[10 Marks]
(A): Choose the correct answer:
2 marks (4 × ½)
1- All the following are from the properties of the cathode rays except they
……………..
a) have a thermal effect
b) move in straight lines
c) are positively charged
d) are affected by both electric and magnetic fields.
2- The greater the value of the principal quantum number (n) the ………… the energy
of the orbital and the ………. the size of the orbital
a) higher, larger
b) higher, smaller
c) lower, smaller
d) lower, larger.
3- In the element (X) of atomic number (14), the electrons are distributed in
…………… sublevels.
a) 1
b) 3
c) 5
d) 7
4- Orbitals of the same sublevel are …………… in energy.
a) close
b) completely different
c) equal
d) none is correct
(B) What are the advantages of Bohr's atomic model?
(C) What is:
3 marks
2 marks (4 × ½)
1- The number which defines the spin motion of the electron around its axis.
2- The rule which explains the distribution of electrons in the orbitals of a given
sublevel.
3- The names of the scientists who performed the gold foil experiment
1
4- The constituents of the cathode rays.
(D) What are the postulates of Dalton's atomic model.
Second question:
3 marks
[10 Marks]
(A) Correct the underlined words in each of the following:
2 marks (4 × ½)
1- The energy level (M) is saturated with 50 electrons.
2- The first scientist who defined the element is Aristotle .
3- The (p) sublevel consists of 5 orbitals of elliptical shape .
(B) Compare between:
4 marks (2 × 2)
1- Subsidiary quantum number and magnetic quantum number
2- Excited state and ground state of an atom.
(C) Write the scientific contribution of the following scientists:
Heisenberg – Sommerfield
2 marks (2 × 1)
(D) Indicate the number of:
2 marks (2 × 1)
1- The unpaired electrons in a boron atom (5B)
2- Energy levels occupied by electrons in an iron atom (26Fe)
Third Question:
[10 Marks ]
(A) Give reasons for:
4 marks (4 × 1)
1- The nineteenth electron of a potassium atom (19K) is located in the fourth energy
level rather than the third energy level.
2- The quantum needed to transfer an electron from the second to the third energy
level is different from the quantum needed to transfer an electron from the third to
the fourth energy level.
3- In gold foil expermint, a very small percentage of alpha particles did not penetrate
the gold foil but were deflected.
4- The behavior of the cathode rays do not differ either by changing the material of
the cathode or the type of gas used.
(B) Write the scientific term for each of the following statements: 2 marks (4 × ½)
2
1- The region of space around the nucleus in which the electron most probable exist.
2- A sublevel consists of seven orbitals
3- A limited number of coloured lines which characterize one element from another.
4- The electron is a material particle which also has wave properties.
(C) Illustrate the valence electrons (electrons of the outer most energy level) of the
following elements according to Hund's rule
3 marks (3 × 1)
Nitrogen (7N) – Aluminum (13Al) – Chlorine (17Cl)
(D) What is the number of the (p) sublevels in the heaviest known atom? `
3
1 mark